Fusing machine



y 3, 1960 E. A. THOMPSON 2,935,596

FUSING MACHINE Filed Dec. 50, 1957 14 Sheets-Sheet 1 76 /lo g I l m UL H 11th, H -W ma E INVENTOR. 52/2; 6 72/0MP50A/ May 3, 1960 E. A. THOMPSON 2,935,596

FUSING MACHINE Filed Dec. 30, 1957 14 Sheets-Sheet 3 INVENTOR. file; /4. 77/0MP50/v )Q /MM /4 T T R NE Y y 1960 E. A. THOMPSON 2,935,596

FUSING MACHINE Filed Dec. 30, 1957 14 Sheets-Sheet 4 INVENTOR. Q 5424 6 fi/oMpso/v A TTo RWE) Y 1960 E. A. THOMPSON 2,935,596

FUSING MACHINE Filed Dec. 30, 1957 14 Sheets-Sheet 5 A I I I II II I l I l l I l J 22 @l l V H INVENTOR. 5mm A fia/vpso/v Maw ATTb (F /v5) y 1960 E. A. THMPSON 2,935,596

FUSING MACHINE Filed Dec. '30, 1957 14 Sheets-Sheet 6 38 49 m2 3 /00 v [76' 4 b 36'? INVENTOR. [nu 14. 7/70/0250 ATTORNEY N MW 1960 I E. A. THOMPSON 2,935,596

FUSING MACHINE Filed Dec. 30, 1957 14 Sheets-Sheet 'T INVENTOR. 54,94 4. /HOMP.50/V

I a May 3, 1930 E. A. THofi PSO N 2,935,596

FUSING MACHINE Filed Dec. 30, 1957 14 Sheebs-Sheet 8 I, Io

INVENTOR.

E. A. THOMPSON FUSING MACHINE May 3; 1960 14 Sheets-Sheet 10 Filed Dec. 30, 195'? ATTORNEY is. A. THOMPSON FUSING momma May 3, 1960 Filed Dec. 30, 1957 14 Sheets-Sheet 11 INVENTOR 54,2; 1% 750M 50 BY A W i [MM ATTORNEY u n te S a e Pate 2,935,596 FUSING MACHINE Earl A. Thompson, Ferndale, Mich.

Application December 30, 1957, Serial No. 706,116

12 Claims. (Cl. 219-101) This application is a continuation-in-part of my copending application, Serial No. 637,589, filed January 31, 1957, for Tappet or Cam Follower and the Art of Making Same, which, in turn, is a continuation-in-part of my application, Serial No. 407,005, filed January 29, 1954, for Tappet or Cam Follower and the Art of Making Same, both now abandoned. V g

This invention relates to apparatus for the electric fusion of metal parts. The invention is more particularly concerned with apparatus for producing fused cast iron and steel tappets for automotive engines in which a cast iron base is directly joined to a tubular steel sleeve or bodyin a single short application of heat and pressure.

It has long been recognized that the wearing properties of cast iron are well suited for service as a follower member in direct contact with an automotive camshaft and j that the body portion of a tappet is most desirably formed nomically. One difiicultyinvolved resides in the differv ence in melting points between cast iron and steel. When a heating current high enough to melt the iron is applied, the steel does not melt but the molten iron will flow as a liquid which instantaneously leaves the zone of juncture, preventing adherence of the two pieces.

It is an object of the present invention to provide an improved apparatus for effectively forming a direct fusion joint between a piece of cast iron and a piece of steel having a higher melting point than the cast iron.

A further object is to provide such an apparatus which will form the joint rapidly by a brief pulse of heavy electric current in a manner somewhat similar to a butt welding apparatus.

Another object is to provide an improved apparatusjfor directly joining a cast iron piece to a steel piece having a higher melting point.

'A further object is to provide such an apparatus in which a pulse of electric heating current, together with the application of a strong compressive force will serve to both fuse the cast iron to the steel at one place and upset the steel into mechanical contact with solid cast iron at another place.

A further object is to provide such an apparatus in which the flow of the molten iron is confined and in which the upsetting of the steel takes place in a manner to eliminate the formation of irregularly projecting nodules of metal so that the finished joint presents a comparatively smooth and regular surface which needs no snagging and may be finished by conventional grinding methods.

It is also an object of this invention to provide an im- "ice proved apparatus for joining cast iron directly to steel by both fusion of the cast iron and mechanical upsetting of the steel wherein the line of demarcation between the two metals in the finished joint is a more intimate bond than has heretofore been possible to obtain and which, when the edge of the joint is machined, is invisible to the unaided eye. 7

Another object is to provide an improved electric fusion apparatus for joining a cast iron part to a steel part in which a die mold is utilized for confining the molten and softened metals to the situs of the joint.

A further object is to provide an apparatus of this character in which cast iron parts may be joined to steel parts with great rapidity automatically.

It is also an object to provide such an apparatus wherein a part to be joined may be clamped between a pair of rotating electrodes.

Another object of the present invention is to provide an improved work handling and current conducting electrode system as a part of such an apparatus.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred form of the present invention is illustrated.

In the drawings:

Figure 1 is a front view of an electric fusion apparatus embodying a preferred form of the present invention.

Figure 2 is a view of a finished valve tappet incorporating a preferred form of the present invention.

Figure 3 is a vertical cross section on line 3-3 of Figure 1.

Figure 4 is a cross section on line 4-4 of Figure 3.

Figure 5 is a plan view of the machine shown in Fig ure 1' partially brokenaway.

' Figure 6 is a partial sectional .view taken on line 6-6 of Figure 5. I

Figure 7 is a partial end view partly in section on line 7-7 of Figure 5.

Figure 8 is a fragmentary cross section taken on line 8-8 of Figure 5.

Figure 9 is a fragmentary sectional view on line 9-9 of Figure 5.

Figure 10 is an end view of the machine shown in Figure 1 illustrating the mechanico-hydraulic drive mechanism.

Figure 11 is a diagrammatical view of a mechanico-hydraulic drivemechanism forming part of the machine of Figure l.

. Figure 12 is a fragmentary sectional view taken on line 12-12 of, Figure 1.

Figure 13 is a fragmentary .view of a portion of Figure 5 on a larger scale.

Figure '14 is a fragmentary sectional view on line 14-14 of Figure 13.

Figure 15 is a fragmentary sectional view on line 15-15 of Figure 5.

Figure 16 is a cross sectional view on line 16-16 of Figure 15.

Figure 17 is a sectionabview on line 17-17 of Figure 12. I

Figure 18 is a sectional view on line 18-18 of Figure l0. v

' Figure 19 is a fragmentary sectional view taken on line the parts of 'a two-piece tappet inposition in the machine I of Figure 1 and ready for fusing.

Figure 23 is a view corresponding to Figure 22 showing the starting stage in the fusing operation.

Figure 24 is a view corresponding to Figure 22 showing the complete fused tappet at the conclusion of the fusing operation.

Fi ure 25 is a view of the fused tappet ready for removal from the machine.

Figure 26 is a top view, partly in section, of a Work feeding mechanism forming part of the machine of Figure 1.

Figure 27 is a developed front view of the work feed ing mechanism shown in Figure 26, developed along the line 27-27 of Figure 26.

Figure 28 is a fragmentary sectional view on line 28-48 of Figure 26.

Figure 29 is a top view, partly in section, of another portion of the work feeding mechanism.

Figure 30 is a front view, partly in section, on line Sil -30 of Figure 29.

Figure 31 is a sectional view on line 31-31 of Figure 29.

Figure 32 is a top view partly in section on line 32-32 of Figure 30.

Sliding heads The machine illustrated in the drawings comprises a main box-like base 10, having a generally flat top plate 12. Secured rigidly to the top plate 12 is a Way bed plate 14 extending the full width of the machine for the purpose of carrying a plurality of horizontally shiftable heads. At each end of the bed 14 there is rigidly secured to the top surface thereof a pair of vertically extending thrust brackets 16 and 18, respectively. These brackets are mounted by bolts 19 (Figure 7) and are provided with a small vertical clearance space 20 over most of the central portion of the bed 14.

The bed is provided with a dovetail way 22 having an adjustable gib 24. Slidable within the way 2'2 arefour heads for the purpose of carrying suitable electrodes. At the left-hand end of the way, a head 26 (Figure 9) has a dovetail base 28 slidable in the way 22 and carries an upstanding vertical bracket 30 which has a horizontal arranged nut 32 in its left-hand face. A threaded shaft 34 is rotatable but axially immovable in the thrust bracket 16 and has wrenching flats 36 and a graduated dial 38 at its left end for the purpose of adjusting the position of the head 26 in the way 22.

The bracket 30 carries on its right-hand face a hardened steel hemispherical socket 40 in which is mounted a mating steel ball 42. Opposing the socket40 is a similar socket 44 carried in an electrode jaw member 46, which has a horizontally extending jaw 48 and has a flexible laminated ribbon bus bar 50 secured to its upper portion.

The universal motion permitted by the ball and socket connection 42 is restrained by a plurality of cap screws 52 having springs 54 under their heads and by a corresponding number of adjustable stop bolts 56. Preferably the bolts 52 and 56 are distributed alternately around the axis of the adjusting shaft 34, there being, for example, three of the spring retainer bolts 52 and three of the stop screws 56.

The base 28 has a horizontal bore which receives a rod 58 having adjusting nuts 60 at its left-hand end. The right-hand end of rod 53 is secured in a threaded socket 62 formed in a first turret slide or head 70.

The head has dovetail sides which s-lidably fit the Way 22 and carries anti-friction bearings 72 for journaling a vertical turret shaft 74. The shaft 74 carries at its upper end a turret 76. On its lower'surface, the turret 76 carries a plurality of tapered indexing holes 78 for cooperation with a slidable bolt 80 which has a piston 82 at its lower end, reciprocable in a fluid cylinder 84. Suitable fluid pressure connections 86 and 88 may be provided for operating the piston 84.

The turret 76 and shaft 74 are arranged with circulating Cir water passages to cool the electrodes. Thus, a two-way fluid swivel joint 90 is positioned at the lower end of shaft 74 having an inlet passage 92 and an outlet passage 94. These communicate, respectively, with a central tube 96 and a concentric annular passage 98 in the shaft.

The turret head is hollow and arranged with suitable passages for directing the incoming cooling liquid around the circumference of the turret and back to the outlet passage. The turret head 76 comprises a lower base member 100 upon which an upper electrode member 102 is slidably fitted and sealed at 104. The member 102, as well as the jaw 48 and member 46, are formed of highly conductive material such as a copper alloy. The periphery of the member 102 is cylindrical and mates with the corresponding face of jaw 48 when the turret is positioned as shown in Figure 5. The cylindrical periphery is interrupted in five or more places to form Work piece receiving cavity halves later to be described.

A third slide, or head, 108 is mounted in the way 22 and carries another turret 110. The head 108 and turret 110 may be similar to head 70 and turret 76 except that the indexing holes and pin may be omitted. The fourth movable slide is indicated at 112 and may be similar to slide 26 except for its connection with thrust bracket 18.

The construction of the latter is illustrated in Figures 6 and 7 and includes a nut block 114 secured to the head 112 at its right-hand end. The block 114 may have a cylindrical exterior slidably fitted in a stationary sleeve 116, which is secured to the end face of thrust bracket 18. l'ournalcd upon anti-friction thrust bearings is a screw shaft 122 threaded in the nut block 114 and having a pinion 124 at its right-hand end. A rack 126 meshes with pinion 124.

As illustrated in Figure 7, the rack 126 is formed upon a cylindrical double acting piston 128 which is slidable in cylinder 130 formed in the thrust block 18. Suitable adjustable stops pins 134 and 136 limit the stroke of the piston 128. Fluid connection ports 138 and 140 are provided at each end of the cylinder as well as necessary air bleed valves 142 and 144.

The arrangement of the four heads 26, 70, 108, and 112 is such that the first head 26 remains in a stationary position which may be adjusted by the threaded shaft 34. The head 7 G is biased to the right by a spring 146 (Figure 9) tending to separate the turret 76 from the jaw 48 by a small distance. The adjusting nuts 6tldetermine this distance and limit the expansion of the spring 146. As shown in Figure 6 a similar construction is employed between the heads 108 and 112 and, once the spring-146 has expanded to bring thenuts 60 into contact with head 112, the two heads 112 and 108 may be'shifted to the right as a unit bythe action of the threaded shaft 122 in thenut 114. Movement of the head 112 to the left, however, will apply a compressive force to bring'all four heads into abutment, compressing the springs 146 and serving to hold a work piece between the pair of cavity halves 166 which are facing each other'in the turrets 76 and 110.

The'cavity halves may be identical on both turrets and are shown in detail in Figures 13 and 14. They are preferably formed as half-annular liners of welding electrode alloy as indicated at 148. These may be retained by cap screws 150at either edge-of the liner 148. Preferably one or more contact rings 152 of special electrode alioy material are brazed into the liner halves 148 for the purpose of contacting the work piece to transfer the heavy current thereto.

Positioned in an annular groove 154, formed in the liner 148,-is-an annular die member 156, which is formed of stainless steel. The die 156 is insulated from the liner 148 by insulation 158 and retained by screws 160 which are also insulated from jaw 148 by insulation 162. Mica, fiberglass or similar material may be usedfor insulation.

The bed plate 14 carries at its mid portion a stationary block 164, Figures 15 and 16, which has a cylindrical asserts recess 166 closed by a cover 168. Within the recess is a rotatable nut sleeve 170 within which is threaded a hollow work piece abutment 172 having a hardened, wear resistant insert 174 at its upper end.

The nut 170 is provided with ring gear'176 which meshes with a worm 178 mounted on a shaft 180 which is rotatably secured in theblock 164 and has a hexagon socket head 182 for purposes of turning the same. The shaft 180 is journaled in a bushing 184 which is retained in the block 164 by a set screw 186. A second set screw 188 serves to lock the shaft 180 in any adjusted position.

The base is provided with a fore and aft vertical bulk head 190 upon which is mounted a hydraulic motor 192 having a piston 194 and suitable fluid connections 196 and 198. The rod 200 of piston 194 carries, by means of couplings 202 and rod 204, a vertically reciprocating centering pin 206. The upper end of pin 206 is slidably received in the hollow nut 172 and insert 174. The upper end of pin 206 is chamfered to act as a centering media for a work piece part having a hollow tapered cavity as indicated in dotted lines at 208.

Head As shown in Figures 1 and 3, the base 10 carries a central upright pressing head, generally designated 210. This comprises a stationary frame member 212 which is supported at the rear by a pedestal 214 and at the front by a post 216. A movable platen 218 has a pair of vertical guide bars 220 securely clamped thereto and reciprocable in hushed bores 222 in the member 212. The platen 218 has a threaded bore 224 at its central portion and is slotted as indicated at 226 (Figure 4) for the purpose of adjustably clamping a thrust rod 228 to the platen 218 by means of clamping screws 230.

The frame member 212 carries an operating cylinder assembly 232 centrally on its upper portion. This may comprise a first hydraulic cylinder 23-4 in which a piston 236 is slidable. The piston 236 is connected to the thrust rod 228. Suitable hydraulic connections 238 and 240' connect with the lower and upper ends of cylinder 234, respectively. The connection 240 enters through a plurality of radial ports in a bushing 242 within which is slidably mounted an intensifier plunger 244. The bushing 242 opens at its lower end directly into the cylinder 234. g

The plunger 244 carries an air piston 246 at its upper end. The piston 246 is of considerably larger diameter and is slidable in a cylinder 248, the lower end of which; has a vent opening 250. The upper end of cylinder 248 is closed by a disc 252 which also formsthe base of an air accumulator or pressure reservoir indicated at 254. This may receive compressed air from any suitable supply, such as a shop airline 255.

As shown in Figure 19, a solenoid operated threeway air valve 256 controls communication of the upper end of cylinder 248 with accumulator air pressure and exhaust. A conduit 258 connects between the accumulator 254 and the valve 256. A conduit 260 communicates between the cylinder 248 and the valve, while a conduit 262 provides an exhaust from the valve.

On the lower face of the platen 218 there is secured a bus bar 264. The bar is insulated from the platen at 266 as are the holding screws 268. Suitable cooling water inlet and outlet connections are provided at 270 and 272. Secured to the lower face of the bus bar 264 is an electrode holder 274 having a hollow cylindrical electrode 276 projecting downwardly and located centrally above the cavity halves 106 at the point of tangcncy of the turrets 76 and 110.

- As shown in Figures 3 and 5, a finished work ejector guide 277 overlies the turrets 76 and 110 to the rear of the electrode 276. This includes a pair of inclined camming surfaces 279 which lie in the path of the cavity halves as they leave'the tangent point, and thus serve to clear a finished work piece from whichever of. the cavity halves it may happen to cling. An exit chute 281, which is inclined downwardly to the left of the machine, serves to carry finished pieces out to a convenient receptacle or conveyer.

For clarity of illustration, the pipelines and hoses which supply cooling fluid and motive fluid to the various parts described and shown have been omitted from the drawings, it being understood that these connections are established by usual plumbing procedures. Likewise the complete electrical bus bars for supplying fusing current to the electrodes are not shown since they in turn may be arranged according to conventional electrical construction practice.

. Turret index For the purpose of intermittently rotating the turret heads 76 and 110, their operating shafts 74 are provided with universal joint coupling shafts indicated at 278.

These connect with stationary stub shafts 280 journaled in stationary bearing blocks 282 which are secured to a mezzanine base plate 284 in the base 10. The lower end of shafts 280 carry meshing gears 286 and 288 of equal.

size.

The gear 286 has a separate web 290 (Figure 17) which is secured to the rim 292 by several bolts 294,

which operate in arcuate slots 296 for providing angular adjustment of gear 286 relative to shaft 74.

p The gear 286 is driven from an indexing pinion 298 which is keyed to the lower end of a shaft 300. This shaft is arranged having both rotary and reciprocating motion so that the pinion may be lifted up to disengage the gear 286 for performing an idle reverse rotation of the pinion. For this purpose an indexing drive assembly, generally designated 302, is mounted on the plate 284. This includes a pair of anti-friction bearings 304 within which the shaft 300 is slidable and which serve as rotary mountings for the shaft as well.

At its upper end the shaft 300 is provided with a pinion 306 which meshes with a rack 308 formed on a double-acting piston 310 (Figure 12). The width of pinion 306 is substantially double that of the rack so that meshing engagement is not interrupted by vertical translation of the shaft 300. The piston 310 is mounted in a double ended cylinder 312 having end caps 314 provided with adjustable stop screws 316 and with fluid terminal connections 318 and 3-20.

Positioned in the top of index mechanism 302 is an operating cylinder 322 having a piston 324, the rod of which is connected to shaft 300 through a thrust bearing 326. Connection terminals 328 and 330 are provided for motive fluid.

Work piece feeders For the purpose of feeding work pieces to the machine, a guide rail of L-shaped cross section is shown at 410 in Figure 5 and underlies the forward periphery of the left-hand turret 76. The work guide 410 has a flat entry shelf 412 lying under one of the cavity halves 106 where a tubular work piece component may be received. Such a component is indicated at 414 in Figure 29.

An automatic work feeding mechanism for feeding tubular components is shown in Figures 29 through 32. This tube feeder comprises a vertical frame structure 416 mounted upon a base 418 which is secured by a spacer 420 to the base plate 14 of the machine. Associated with the frame structure 416 is a pair of alternately reciprocating shuttles 422 and 424, which are connected for operation by a lever 426 pivoted at 428 on the frame 416. The shuttles may be operated by a fluid motor 385 having fluid connections 383 and 430. The piston 432 has its rod 434 connected to the shuttle 424 for this purpose.

The shuttle 424 has a J-shaped pusher face 436, which, in its projected position as shown in Figures 29 and 30, holds a work piece component 414 in the cavity halves 106, having slid it to this position with its bottomface resting on the guide plate 412, as shown inFigure 30. The upper shuttle 422, in its retracted position shown in the drawings, receives work piece tubes 414 from a gravity or other conveyer tube 438 (Figure 32), which has a horizontal terminus. A horizontal plate 440 supports the work pieces in this position. Suitable vertical side plates 441 and 443 are secured to the plate 440 to form guides for the shuttle 422 and to receive the end of conveyer tube 433. When the shuttle 422 is projected forwardly, it pushes the work piece 414 horizontally along the plate 440 until it falls through a hole 442. The shuttle 422 also blocks entry of the next work piece from the tube 438 until the shuttle returns to the position shown in the drawings.

The hole 422 cooperates with a chute 444 to orient and erect the work pieces with their large ends at the top. Thus, as shown in Figure 32, the end portions of hole 442 are narrower than the central portion so that they permit the small end of the tube to pass, but not the large end. Accordingly a piece presented large end first from the tube 438 will fall through the opening 442, as shown in dotted lines in Figure 31.

The chute 444 completes the erection of the work piece so that it will stand on the guide plate 412 in front of the shuttle 424, which recedes as the shuttle 422 advances. Work pieces which are presented small end forward from the tube 438 will start todrop through the hole 442 at the left-hand end in Figure 31 and will erect themselves with their small ends down in an otherwise similar manner.

For the purpose of feeding the second work piece components, such as the cast iron buttons 446 shown in Figure 26, there is provided a button feeding mechanism illustrated in Figures 26 through 28. This may comprise a curved gravity track 44-8 having side rails 450 and which is inclined, as shown in Figure 27, for the purpose of guiding buttons, one at a time, into a position shown at 466a. A rocking escapement lever 452 is pivoted at 454 and has an operating lever 456 connected by a link 458 with a tripping cam 460 which is pivoted at 462 on a base plate 464 fastened to the base of the machine. 'Suitable vertical frame plates 466 and 468 are secured to base plate 464 to carry other parts of the button feeding mechanism. The tripping cam 46% is engaged by a tubular component 414 as the turret 76 rotates and operates the escapement lever 452 to release the foremost button 446 in the stack while holding the second button against release.

The buttons may be fed to the escapement lever 452 by a suitable gravity or other conveyor running through a preheating oven. Buttons are held in the position 446a by a retractable stop 465 which is pivoted at 467 and has an operating lever 469 connected by a rod 470 to a solenoid 472. The solenoid 472 may be arranged to be actuated through a time delay mechanism, not shown, each time the machine is started up, after having been at rest for a sufficient time for a button to lose its preheat, thus rejecting the first one or more cold buttons.

Mechanico-hydraulic control system For the purpose of moving the various parts of the machine in a proper sequence and for controlling the supply of fusing current, there is mounted on a bracket 332 (Figure 10) at the rear of the base 10 a mechanicohydraulic driving and control unit, generally designated 334, and having an electrical controller section 336. The unit 334 comprises a drive motor 338 connected by a belt 340 to a two-speed transmission gear box 342. The output of the transmission 342 is a single camshaft 344, shown diagrammatically in Figure 11, and running horizontally from left to right in the cam case 346 in Figure 10. The camshaft carries cams which operate hydraulic pulsator transmitters for operating the pistons and various fluid motors connected to the movable parts of the machine. For the purpose of achieving maximum efiiciency of motion, it is desirable to operate the master camshaft 344 at both a rapid speed and a slower feeding speed during different portions of a single revolution thereof. This may be accomplished by a suitable self-controlling two-speed transmission 342, the mechanism of which is shown diagrammatically in Figure 21. Thus, an input shaft 484 may be driven by a pulley 486 from the belt 340 (Figure l0) and drives a hydraulically engageable clutch 488. Reduction gearing 490 connects between input shaft 484 and a countershaft 492, which, at its opposite end, drives by additional reduction gearing 494, n second hydraulically engaged clutch 436. The driven elements of the clutches 488 and 496 are connected to opposite ends of a worm 498 which meshes with a Worm wheel 500 secured to the camshaft 344. A hydraulically engageable brake 502 may hold the worm 433 stationary. For the purpose of controlling the clutches and brake, there is provided a hydraulic control system in the transmission 342 which includes a pump 504 driven from the gearing 494 and having a combined accumulator and relief valve 506 connected to its delivery line. A solenoid operated start-stop valve 508 is controlled by a solenoid 510 and serves in its normal position to establish the connections shown in the cross-hatched upper rectangle and, when energized, to establish the connections shown in the lower rectangle. In this diagram, double-headed arrows indicate pressure fluid from the pump delivery line, and single-headed arrows indicate exhaust to the reservoir, which may be formed by the housing for transmission 342.

The start-stop valve 508 also controls the fluid supply to a speed shifting valve 512, which is spring biased to establish the connections shown in the cro-ss hatched rectangle. Valve 512 may be shifted to establish the connections of the lower rectangle by an adjustable tripping cam 514 on the camshaft 34-4. A hydraulic'holding cylinder 516 holds the valve 512 in its shifted position until it is released by a reset valve 518, which is controlled by an adjustable cam 520 on the camshaft 344. It will be seen that, in the position shown in Figure 21, valve 538 maintains the brake 502 applied with hydraulic pressure from the pump and accumulator, and, together with the valve 512, maintains the slow speed clutch 496 disengaged by exhausting the same. Valve 512 alone exhausts the high speed clutch 488.

If solenoid 510 is energized, brake 502 is released and slow speed clutch 496 is engaged by pressure from the pump through valves 508 and 512, with the high speed clutch 4S8 remaining disengaged. When the cam 514 shifts valve 512, the slow speed clutch 496 will be disengaged and the high speed clutch 488 will be engaged. This condition will maintain until cam 520 operates the reset valve 518 to bypass the holding cylinder 516 and reset valve 512.

The camshaft 344 also carries an extension camshaft running into the electrical controller 336 for operating electric switches which control the application of fusing current and control the stopping of the transmission 342.

The base 19 also carries on its rear wall (Figure 5) a liquid reservoir or accumulator 348 for maintaining a plenary supply of oil under pressure which may be utilized to bias the various motive cylinders in one direction. For'this purpose a return oil manifold 356 leads from the reservoir 348 and has branches leading to the various connection ports of the motive cylinders. The reservoir 348 may be a closed chamber containing a body of liquid together with a body of air under pressure above the liquid. Such air may be supplied from any convenient source such as a shop airline, and if the shopline pressure is not maintained high enough, a self-actuated intensifier of known construction may be utilized as shown at 352.

The hydraulic connections for the cam unit 334 are indicated diagrammatically in Figure 11. Here the return oil connections are indicated by a circle containing the letters R0, it being understood that although these are shown separately, a common manifold and accumulator, as disclosedat 350 and 348, is preferred for all such return oilconnections. The camshaft 344 carries a plurality of cams, each of which actuates one of the singleacting pulsator units 354, 356, 35-8, 360, 362, 364, 366, 367, and369. These comprise a single-acting piston and cylinder operated by its respective cam and follower. The contours of the cams and displacements of the pulsators are chosen to produce the particular program of motions, speeds, accelerations, sequences, and overlappings desired for the machine parts to be motivated.

A balancing valve in the form of a combined relief and replenishing valve, such as indicated at 368, is provided for each pulsator and serves to blow off a slight excess of transmitter displacement at the end of a motor stroke and to replenish the liquid column at the end of the retraction strokeof the transmitter piston. For this purpose the valve 368 communicates through a passage 370 with an oil reservoir 372 positioned immediately over the transmitter cylinder.

The pulsator unit 354 connects by a liquid column line 374 with connection 240 leading to the motor cylinder 234 for the vertical electrode platen. The pulsator unit 356 connects by a liquid column line 376 with the connection 138 to the cylinder 130 for the'electrode clamping screw. Unlike the other motive cylinders, the cylinder 130 is not connected at its opposite end with the return oil accumulator manifold 350, but instead the connection 140 is connected by a liquid column line 378 with the pulsator unit 360. The contour of the cams for the pulsators 356 and 3.60 is arranged so that the receding portion of each cam recedes slightly ahead of the advance of the other cam. The pulsator 358 is connected by a liquid column line 379 to the connection 86 of the turret lock bolt cylinder 84.. The pulsator 362 is connected by a liquid column conductor 380 with the connection 196 of the cylinder 192 which operates the centering pin 206. The pulsator 364 is connected by a liquid column line 382 with the connection 320 of' indexing cylinder 312, while pulsator 366 is connected by a liquid column line 384 with the connection 330 of cylinder 332.

The pulsator 367 connects by a liquid column line 381 with connection 383 of cylinder 385 of the work feeding mechanism. Likewise, pulsator 369 connects by liquid column 387 with connection 389 of cylinder 391.

Mounted on the rear of the base (Figure 5) is a transformer 386 which is of conventional form such as used in electric welding machines and has a bus bar 387 which connects by a pair of flexible laminated ribbon connectors 388 with the bus bar 264 (Figure l) on the platen 218. The other output terminal of the transformer is connected by a bus bar 390 with the flexible connectors 50 leading to the electrode clamping jaws 46 and 48.

' Electric control system which are adjustable angularly on the shaft and which are formed of two leaves adjustably. clamped together by screws 394 which extend through slotsv 396. A bracket 398 on the side of the cam case 336 carries a plurality of limit switches 400, 402, 404 and 406, each of which has a roller plunger 408 for cooperating with its respective cam 39.2.

The machine also includes a system of switches and,

relays for control of the over-all functions as illustrated diagrammatically in Figure 20. This system may is located in a suitable electric panel box, not illustrated,

and may incorporate therein suitable heating current con-' trols for the transformer 386.

Referring now to Figure 20, there is shown a suitable power supply, designated L-l and L-2, and emergency relay CR-E of the holding type manually controlled in oil accumulator 348, byair pressure in the intensifier' supply chamber 254, and by electrical overload.

' Relay CR-M controls one of two alternate preparatory circuits for relay CR-Ml, which may be energized by a normally open'manual start switch 538 having the usual holding circuit in shunt therewith. Relay CR -Md, has an additional preparatory circuit controlled by the lower contacts of a relay CR-1. Thus, relay CR-MI may be manually energized if either of the relays CR-M and CR-l are deenergized and can be deenergized onlyby opening both CR-M and CR-l. Relay CR-l is under 'the sole control of the cam operated limit switch 400 in the electrical cam box.. This switch 400 is opened onlywhen the camshaft 344 reaches a predetermined position, which is the starting and ending point of a cam cycle.

Thus, unlike relay CR-E, the relay CR-M, if dropped out by the master stop switch 528, will not deenergize CR-Ml immediately, but this action will be deferred until cam switch 400 is opened at the end of a cam cycle.

Relay CR-Ml controls a cycle relay CR4 and also a motor relay 540, which, when energized, energizes the electric motor 338 for the mechanico-hydraulic drive andcontrol unit 334. Relay CR-S has the usual holding type start and stop circuit under the control of manual start switch 542 and manual stop switch 544. The start solenoid 510 (Figure 21) for the mechanico-hydraulic unit is under the control of a relay CR-2, which in turn is controlled by two alternate energizing circuits. The first is the upper contacts of relay CR-l. This insures that relay CR-2 remains energized until the end point of the cam cycle as determined by the limit switch 400.

The other energization circuit for relay CR2 includes an indexinterlock switch 546 having a set of normally open contacts in series with the lower contactsof relay CR-S. Interlock switch 546 is arranged to be actuated by any one of five cam dogs 548 (Figure 1) which are located on the bottom of gear 288 so as to actuate the switch 548 each time the turret 76 is brought into properly indexed position. The purpose of this switch is merely precautionary in the event that a malfunction of the apparatus should prevent the turrets from indexing. Also in the alternate energization circuit for relay CR-Z are the lower contacts of a latching type relay LCR-4;

which is unlatched by a coil UCR-4.

The latching coil LCR-4 is energized by a set of nor-; mally closed contacts 547 on the index switch 546 and may be also manually energized by a switch 550. The unlatching coil UCR4 is energized once each revolution of the camshaft 344 by'the switch 402 of the electrical cam box 336. This may occur at some point after completion of a turret indexing motion.

Thus, relay CR-2, which starts and stops the camshaft,

index switch 546, the lower contacts of relay CR-'-S, and the contacts'of latching relay LCR-4. 'On' the other" hand, during the progress of a camshaft revolution, the latching relay is unlatched by cam switch 402, which energizes unlatching coil UCR-A, thus assuring that the camshaft will stop at the end of that revolution, unless the turret thereafter indexes. If the turret does not index, then the upper contacts 547 of index switch 546 will prevent the latching relay from being reclosed by LCR-4 and CIR-1 will deenergize CR-2 as the end of a cam cycle is reached.

For the purpose, of controlling the application of heating current, a relay CR-5 is provided and is energized by switch 404 in the electrical cam box 336 at the appropriate time in the machine cycle. Relay CR-S operates a relay 552 provided in the control circuit, not shown, for the transformer 386. This control relay is also in series with contacts controlled by a relay 554, which in turn is under the control of a manually operated Weldno weld switch 556. The solenoid valve 256 for admitting air to the intensifier 232 is under the control of a relay CR-3, which in turn is energized once each cam revolution at the proper point by the fourth switch 406 in the cam box 334.

Operation In operation with the mechanico-hydraulic unit 334 stopped in its normal stopping position, with the turrets indexed to the cavity meshing position shown in Figure 5, and with a supply of tubular components available in the tube feeder and a supply of buttons available for the button feeder, a cycle may be started by first operating the start switch 522 to close relays CR-E and CR-M, start switch 538 to start the electric motor 338, and then operating start switch 542 to energize relay CR-S. With no parts in the cavity halves of the turrets 76 and 110 to start with, the cam for liquid column 381 operates motor 385 through a forward and return stroke, starting and ending at the position shown in Figures 29 and 30. Thereupon the liquid column 387 operates the motor 391 for the button pusher 474. As explained hereafter, this takes place during an interval sometime after the normal starting point of a cycle and while the camshft 344 is rotating at its rapid speed. A convenient time may be just prior to the starting of the turret unclamping motion of the piston 128.

During the initial few cycles, while the first parts are going into the machine to fill the three stations on turret 76, the machine goes through the motions of performing fusion operations. These motions and the further motions of feeding work pieces tothe proper stations on turret 76 will be described starting at the appropriate point in the rotation of camshaft 344 where the fusing operation would normally be completed and the speed shifting cam 514 (Figure 12) shifts the valve 512 causing the camshaft to rotate at rapid speed. At about the same time the cams for the liquid columns 376 and 378, which operate the fluid motor 130 for the turret clamping screw 122, begin to move the piston 128 so as to retract the head 112. Its first motion to the right separates-jaw 48 from turret 110 until it picks up the nuts 60 at the right-hand end of the machine, thus beginning to move the head 108 for turret 110. During the first part of this motion, the spring 146 at the left end of the machine pushes the head 70 for the turret 76 to the right until nuts 60 are contacted, thus separating turret 76 from its jaw 48. Thereafter the further travel of head 112 to the right separates the turret 110 from the turret 76 at the meshing point.

After the turrets are thus separated, the cam for the indexing rack motor 312 operates the rack piston 310 through the liquid column 382, moving it from its lefthand position to the right-hand position shown in Figure 12. This, through the gearing 286, 288, and 298, indexes the turrets 7 6 and 110 through a fifth of a revolution so that the five work piece cavity halves advance one step. Since the tube feeder mechanism has positioned a tubular component 414 in the cavity half 106, as shown in Fig ures 26, 29, and 30, the first motion of the turret will cause the work piece 414 to actuate cam 460 counterclockwise in Figure 26, thus tripping the escapement lever. 452 and allowing a button 446 to roll down to the position 446a. The first one or more of such buttons to roll down will be permitted to roll off the end of the trackbecause stop 465 (Figure 27) will have been raised by its solenoid 472 and the first one or more of the tubes 414 will pass through the machine without receiving a button. Liquid column 379 for the lock pin motor 84 will thereupon raise the lock pin 80.

On the next indexing cycle after the stop 465 is lowered, the button released by cam 460 will stop in position 446a. In the meantime, the appropriate cam will have driven the shuttle motor 385 and the button pusher motor 391, feeding another work piece 414 and causing the pusher 474 to tip the button 446 into position on top of the work piece tube 414 and then to return and retract the pusher 474.

At about the same time the cams for the turret clamping rack operate the piston 128 to reclamp the turrets between the two heads 26 and 112, thus holding the tubular work piece between the cavity halves and establishing good electric contact through the ring 152 (Figure 14) and positioning the insulated die 156 along side the crack between the two work piece components, as shown in Figures 22 and 23. For tight contact, a clearance as shown at 570 in Figure 13 is allowed.

Since there is considerable diametral play between the button and the tube where they telescope together, it is desirable to center the button with respect to the tube. For this purpose the cam for the centering pin motor 192 (Figure 15) raises the piston 194 to bring the centeringv pin 206 upwardly to the position shown in Figure 22, where its tapered end centers thebutton 446 by means of its tapered interior configuration. This may complete the rapid portion of the cam cycle and the transmission may be tripped into slow speed by cam 520.

At about the same time, the turret indexing mechanism may return, and for this purpose the appropriate cam operates the disengaging motor 322 in Figure 17 to lift the drive pinion 298 out of engagement with gear 286 so that the indexing motor 312 may be returned to the position shown in Figure 12. While the centering pin 206 remains up, the cam for the electrode cylinder 234 lowers the electrode 276 into contact with the button, and thereafter the centering pin is lowered by the recession of its cam. Thereupon the electrical cam switch 406 closes to energize relay CR-3, which in turn energizes the solenoid valve 256. This operatesthe intensifier piston 246 and its ram 244 descends closing the port 240 and applying intensifier pressure in the upper end of cylinder 234. Very shortly thereafter the electrical cam switch 404 closes to energize relay CR-S, which energizes the control relay 552 to apply the fusing heat through the transformer 386.

Joint fusion The tubular work piece rests upon the adjustable stop 174, shown in Figure 15, and the intensifier applies a high pressing force, pushing the button into the end of the tube. The application of the heating current along with the pressure causes the upper end of the steel tube to soften, but not melt, and results in a swaging, or upsetting, of the tube wall, both inwardly and outwardly in a radial direction. Thus, the steel is swaged into mechanical contact with the side wall of the telescoping portion of the button and is also swaged outwardly into contact with the insulated die 156.

At the same time the cast iron is heated above its melting point locally adjacent the contacting faces of the two parts. The molten cast iron tends to flow away from the joint face at first, but is prevented from flowing inwardly by the mechanical seal established by the inwardly upset end of the tube. Thus, the molten cast iron may only 

